Introduction



As shown in the graph below, at any given time of the year, the global ratio of men to women is approximately equal. However, this balance can be deceptive when viewed at a deeper level. In this analysis, I will explore whether this equality holds across different age groups. If it does, what factors maintain it? If not, what forces are driving disparities in the gender ratio as people age? Through this investigation, I aim to uncover the hidden dynamics shaping the global gender balance.





Data Source: Multiple sources compiled by World Bank (2024) – processed by Our World in Data

Sex ratio per Age Group



Interestingly, men tend to outnumber women up until their 30s, after which their numbers begin a steady decline. This pattern is particularly striking given that male infants are biologically more susceptible to disease and have higher rates of infant mortality. It raises an intriguing question: how can the global gender balance remain equal on average when men’s life expectancy starts to drop so early? This observation suggests that deeper forces are at play in maintaining or disrupting this balance.







Missing Women



“Missing women” refers to the number of women who would be alive today if not for sex-based discrimination and harmful societal practices. This includes the number of girls who are never born due to sex-selective abortion, and the excess female mortality caused by infanticide or neglect. On average, there are approximately 2,837,273 missing women annually. As of the latest data collection in 2015, China led the world, accounting for 43% of the missing women, followed by India at 30%, and the rest of the world contributing the remaining 25%. However, it’s important to note that China and India together make up about 2/8 of the world’s population, which suggests that this data may be disproportionately influenced by these two countries. This could skew the numbers, although it also points to the challenges these nations face in addressing sex-selective practices. Despite governmental bans on sex-selective abortion in both China and India, the persistence of these practices suggests that policies alone have not been entirely successful in eradicating the problem. This highlights the deep-rooted cultural preferences for male children and the complex barriers to change.







Data Source: Missing women estimates (Bongaarts & Guilmoto, 2015) – processed by Our World in Data

Causes of Death in Males



Substance use disorders and cardiovascular diseases are among the leading causes of death worldwide, with both conditions being notably more prevalent in men than women. These health issues likely contribute to the decline in the male population as they age, particularly as the onset of substance use and experimentation often occurs in one’s 20s and 30s. As seen in the data for 2021, women had a death rate of 217,057.3 due to substance abuse, while men had a significantly higher rate of 780,909.1. A similar trend is observed with cardiovascular disorders, which, although declining globally, still disproportionately affect men, leading to higher mortality rates compared to women. This further supports the notion that men’s higher mortality rates in adulthood are influenced by both lifestyle factors, such as substance use, and health conditions, such as cardiovascular diseases.







Conclusion




The gender imbalance in global populations is not only shaped by biological factors but also by significant behavioral and health-related disparities. While women face early-life discrimination, men face higher mortality rates in adulthood due to higher rates of substance abuse, cardiovascular diseases, and other risk-taking behaviors. These factors combine to create a complex and dynamic picture of gender and survival across age groups, highlighting the importance of addressing both social and health factors to improve life expectancy for both genders.